What, then, was the survival value of naked skin? One explanation is that when the hunting ape abandoned its nomadic past and settled down at fixed home bases, its dens became heavily infested with skin parasites. The use of the same sleeping places night after night is thought to have provided abnormally rich breeding-grounds for a variety of ticks, mites, fleas and bugs, to a point where the situation provided a severe disease risk. By casting off his hairy coat, the den-dweller was better able to cope with the problem.
There may be an element of truth in this idea, but it can hardly have been of major importance. Few other den-dwelling mammals – and there are hundreds of species to pick from – have taken this step. Nevertheless, if nakedness was developed in some other connection, it might make it easier to remove troublesome skin parasites, a task which today still occupies a great deal of time for the hairier primates.
Another thought along similar lines is that the hunting ape had such messy feeding habits that a furry coat would soon become clogged and messy and, again, a disease risk. It is pointed out that vultures, who plunge their heads and necks into gory carcasses, have lost the feathers from these members; and that the same development, extended over the whole body, may have occurred among the hunting apes. But the ability to develop tools to kill and skin the prey can hardly have preceded the ability to use other objects to clean the hunters’ hair. Even a chimpanzee in the wild will occasionally use leaves as toilet paper when in difficulties with defecation.
A suggestion has even been put forward that it was the development of fire that led to the loss of the hairy coat. It is argued that the hunting ape will have felt cold only at night and that, once he had the luxury of sitting round a camp fire, he was able to dispense with his fur and thus leave himself in a better state for dealing with the heat of the day.
Another, more ingenious theory is that, before he became a hunting ape, the original ground ape that had left the forests went through a long phase as an aquatic ape. He is envisaged as moving to the tropical sea-shores in search of food. There he will have found shellfish and other sea-shore creatures in comparative abundance, a food supply much richer and more attractive than that on the open plains. At first he will have groped around in the rock pools and the shallow water, but gradually he will have started to swim out to greater depths and dive for food. During this process, it is argued, he will have lost his hair like other mammals that have returned to the sea. Only his head, protruding from the surface of the water, would retain the hairy coat to protect him from the direct glare of the sun. Then, later on, when his tools (originally developed for cracking open shells) became sufficiently advanced, he will have spread away from the cradle of the sea-shore and out into the open land spaces as an emerging hunter.
It is held that this theory explains why we are so nimble in the water today, while our closest living relatives, the chimpanzees, are so helpless and quickly drown. It explains our streamlined bodies and even our vertical posture, the latter supposedly having developed as we waded into deeper and deeper water. It clears up a strange feature of our body-hair tracts. Close examination reveals that on our backs the directions of our tiny remnant hairs differ strikingly from those of other apes. In us they point diagonally backwards and inwards towards the spine. This follows the direction of the flow of water passing over a swimming body and indicates that, if the coat of hair was modified before it was lost, then it was modified in exactly the right way to reduce resistance when swimming. It is also pointed out that we are unique amongst all the primates in being the only one to possess a thick layer of sub-cutaneous fat. This is interpreted as the equivalent of the blubber of a whale or seal, a compensatory insulating device. It is stressed that no other explanation has been given for this feature of our anatomy. Even the sensitive nature of our hands is brought into play on the side of the aquatic theory. A reasonably crude hand can, after all, hold a stick or a rock, but it takes a subtle, sensitized hand to feel for food in the water. Perhaps this was the way that the ground ape originally acquired its super-hand, and then passed it on ready-made to the hunting ape. Finally, the aquatic theory needles the traditional fossil-hunters by pointing out that they have been singularly unsuccessful in unearthing the vital missing links in our ancient past, and gives them the hot tip that if they would only take the trouble to search around the areas that constituted the African coastal sea-shores of a million or so years ago, they might find something that would be to their advantage.
Unfortunately this has yet to be done and, despite its most appealing indirect evidence, the aquatic theory lacks solid support. It neatly accounts for a number of special features, but it demands in exchange the acceptance of a hypothetical major evolutionary phase for which there is no direct evidence. (Even if eventually it does turn out to be true, it will not clash seriously with the general picture of the hunting ape’s evolution out of a ground ape. It will simply mean that the ground ape went through a rather salutary christening ceremony.)
An argument along entirely different lines has suggested that, instead of developing as a response to the physical environment, the loss of hair was a social trend. In other words it arose, not as a mechanical device, but as a signal. Naked patches of skin can be seen in a number of primate species and in certain instances they appear to act as species recognition marks, enabling one monkey or ape to identify another as belonging to its own kind, or some other. The loss of hair on the part of the hunting ape is regarded simply as an arbitrarily selected characteristic that happened to be adopted as an identity badge by this species. It is of course undeniable that stark nudity must have rendered the naked ape startlingly easy to identify, but there are plenty of other less drastic ways of achieving the same end, without sacrificing a valuable insulating coat.
Another suggestion along the same lines pictures the loss of hair as an extension of sexual signalling. It is claimed that male mammals are generally hairier than their females and that, by extending this sex difference, the female naked ape was able to become more and more sexually attractive to the male. The trend to loss of hair would affect the male, too, but to a lesser extent and with special areas of contrast, such as the beard.
This last idea may well explain the sex differences as regards hairiness but, again, the loss of body insulation would be a high price to pay for a sexy appearance alone, even with subcutaneous fat as a partial compensating device. A modification of this idea is that it was not so much the appearance as the sensitivity to touch that was sexually important. It can be argued that by exposing their naked skins to one another during sexual encounters, both male and female would become more highly sensitized to erotic stimuli. In a species where pair-bonding was evolving, this would heighten the excitement of sexual activities and would tighten the bond between the pair by intensifying copulatory rewards.
Perhaps the most commonly held explanation of the hairless condition is that it evolved as a cooling device. By coming out of the shady forests the hunting ape was exposing himself to much greater temperatures than he had previously experienced, and it is assumed that he took off his hairy coat to prevent himself from becoming over-heated. Superficially this is reasonable enough. We do, after all, take our jackets off on a hot summer’s day. But it does not stand up to closer scrutiny. In the first place, none of the other animals (of roughly our size) on the open plains have taken this step, If it was as simple as this we might expect to see some naked lions and naked jackals. Instead they have short but dense coats. Exposure of the naked skin to the air certainly increases the chances of heat loss, but it also increases heat gain at the same time and risks damage from the sun’s rays, as any sun-bather will know. Experiments in the desert have shown that the wearing of light clothing may reduce heat loss by curtailing water evaporation, but it also reduces heat gain from the environment to 55 per cent of the figure obtained in a state of total nudity. At really high temperatures, heavier, looser clothing of the type favoured in Arab countries is a better protection tha
n even light clothing. It cuts down the in-coming heat, but at the same time allows air to circulate around the body and aid in the evaporation of cooling sweat.
Clearly the situation is more complicated than it at first appears. A great deal will depend on the exact temperature levels of the environment and on the amount of direct sunshine. Even if we suppose that the climate was suitable for hair loss – that is, moderately hot, but not intensely hot – we still have to explain the striking difference in coat condition between the naked ape and the other open-country carnivores.
There is one way we can do this, and it may give the best answer yet to the whole problem of our nakedness. The essential difference between the hunting ape and his carnivore rivals was that he was not physically equipped to make lightning dashes after his prey or even to undertake long endurance pursuits. But this is nevertheless precisely what he had to do. He succeeded because of his better brain, leading to more intelligent manœuvring and more lethal weapons, but despite this such efforts must have put a huge strain on him in simple physical terms. The chase was so important to him that he would have to put up with this, but in the process he must have experienced considerable over-heating. There would be a strong selection pressure working to reduce this over-heating and any slight improvement would be favoured, even if it meant sacrifices in other directions. His very survival depended on it. This surely was the key factor operating in the conversion of a hairy hunting ape into a naked ape. With neoteny to help the process on its way, and with the added advantages of the minor secondary benefits already mentioned, it would become a viable proposition. By losing the heavy coat of hair and by increasing the number of sweat glands all over the body surface, considerable cooling could be achieved – not for minute-by-minute living, but for the supreme moments of the chase – with the production of a generous film of evaporating liquid over his air-exposed, straining limbs and trunk.
This system would not succeed, of course, if the climate were too intensely hot, because of damage to the exposed skin, but in a moderately hot environment it would be acceptable. It is interesting that the trend was accompanied by the development of a sub-cutaneous fat layer, which indicates that there was a need to keep the body warm at other times. If this appears to counterbalance the loss of the hairy coat, it should be remembered that the fat layer helps to retain the body heat in cold conditions, without hindering the evaporation of sweat when over-heating takes place. The combination of reduced hair, increased sweat glands, and the fatty layer under the skin appears to have given our hard-working ancestors just what they needed, bearing in mind that hunting was one of the most important aspects of their new way of life.
So there he stands, our vertical, hunting, weapon-toting, territorial, neotenous, brainy Naked Ape, a primate by ancestry and a carnivore by adoption, ready to conquer the world. But he is a very new and experimental departure, and new models frequently have imperfections. For him the main troubles will stem from the fact that his culturally operated advances will race ahead of any further genetic ones. His genes will lag behind, and he will be constantly reminded that, for all his environment-moulding achievements, he is still at heart a very naked ape.
At this point we can leave his past behind us and see how we find him faring today. How does the modern naked ape behave? How does he tackle the age-old problems of feeding, fighting, mating, and rearing his young? How much has his computer of a brain been able to reorganize his mammalian urges? Perhaps he has had to make more concessions than he likes to admit. We shall see.
2
SEX
SEXUALLY THE NAKED ape finds himself today in a somewhat confusing situation. As a primate he is pulled one way, as a carnivore by adoption he is pulled another, and as a member of an elaborate civilized community he is pulled yet another.
To start with, he owes all his basic sexual qualities to his fruit-picking, forest-ape ancestors. These characteristics were then drastically modified to fit in with his open-country, hunting way of life. This was difficult enough, but then they, in turn, had to be adapted to match the rapid development of an increasingly complex and culturally determined social structure.
The first of these changes, from a sexual fruit-picker to a sexual hunter, was achieved over a comparatively long period of time and with reasonable success. The second change has been less successful. It has happened too quickly and has been forced to depend upon intelligence and the application of learned restraint rather than on biological modifications based on natural selection. It could be said that the advance of civilization has not so much moulded modern sexual behaviour, as that sexual behaviour has moulded the shape of civilization. If this seems to be a rather sweeping statement, let me first put my case and then we can return to the argument at the end of the chapter.
To begin with we must establish precisely how the naked ape does behave today when indulging in sexual behaviour. This is not as easy as it sounds, because of the great variability that exists, both between and within societies. The only solution is to take average results from large samples of the most successful societies. The small, backward, and unsuccessful societies can largely be ignored. They may have fascinating and bizarre sexual customs, but biologically speaking they no longer represent the mainstream of evolution. Indeed, it may very well be that their unusual sexual behaviour has helped to turn them into biological failures as social groups.
Most of the detailed information we have available stems from a number of painstaking studies carried out in recent years in North America and based largely on that culture. Fortunately it is biologically a very large and successful culture and can, without undue fear of distortion, be taken as representative of the modern naked ape.
Sexual behaviour in our species goes through three characteristic phases: pair-formation, pre-copulatory activity, and copulation, usually but not always in that order. The pair-formation stage, usually referred to as courtship, is remarkably prolonged by animal standards, frequently lasting for weeks or even months. As with many other species it is characterized by tentative, ambivalent behaviour involving conflicts between fear, aggression and sexual attraction. The nervousness and hesitancy is slowly reduced if the mutual sexual signals are strong enough. These involve complex facial expressions, body postures and vocalizations. The latter involve the highly specialized and symbolized sound signals of speech, but equally importantly they present to the member of the opposite sex a distinctive vocalization tone. A courting couple is often referred to as ‘murmuring sweet nothings’ and this phrase sums up clearly the significance of the tone of voice as opposed to what is being spoken.
After the initial stages of visual and vocal display, simple body contacts are made. These usually accompany locomotion, which is now considerably increased when the pair are together. Hand-to-hand and arm-to-arm contacts are followed by mouth-to-face and mouth-to-mouth ones. Mutual embracing occurs, both statically and during locomotion. Sudden spontaneous outbursts of running, chasing, jumping and dancing are commonly seen and juvenile play patterns may reappear.
Much of this pair-formation phase may take place in public, but when it passes over into the pre-copulatory phase, privacy is sought and the subsequent patterns of behaviour are performed in isolation from other members of the species as far as is possible. With the pre-copulatory stage there is a striking increase in the adoption of a horizontal posture. Body-to-body contacts are increased in both force and duration. Low-intensity side-by-side postures repeatedly give way to high-intensity face-to-face contacts. These positions may be maintained for many minutes and even for several hours, during which vocal and visual signals become gradually less important and tactile signals increasingly frequent. These involve small movements and varying pressures from all parts of the body, but in particular from the fingers, hands, lips and tongue. Clothing is partially or totally removed and skin-to-skin tactile stimulation is increased over as wide an area as possible.
Mouth-to-mouth contacts reach their highest freque
ncy and their longest duration during this phase, the pressure exerted by the lips varying from extreme gentleness to extreme violence. During the higher-intensity responses the lips are parted and the tongue is inserted into the partner’s mouth. Active movements of the tongue are then used to stimulate the sensitive skin of the mouth interior. The lips and tongue are also applied to many other areas of the partner’s body, especially the ear-lobes, the neck and the genitals. The male pays particular attention to the breasts and nipples of the female, and the lip and tongue contact here becomes extended into more elaborate licking and sucking. Once contacted, the partner’s genitals may also become the target for repeated actions of this kind. When this occurs, the male concentrates largely on the female’s clitoris, the female on the male’s penis, although other areas are also involved in both cases.
In addition to kissing, licking and sucking, the mouth is also applied to various regions of the partner’s body in a biting action of varying intensities. Typically this involves no more than soft nibbling of the skin, or gentle nipping, but it can sometimes develop into forceful and even painful biting.
Interspersed between bouts of oral stimulation of the partner’s body, and frequently accompanying it, there is a great deal of skin manipulation. The hands and fingers explore the whole body surface, concentrating especially on the face and, at higher intensities, on the buttocks and genital region. As in oral contacts, the male pays particular attention to the female’s breasts and nipples. Wherever they move, the fingers repeatedly stroke and caress. From time to time they grasp with great force and the fingernails may be dug deeply into the flesh. The female may grasp the penis of the male, or stroke it rhythmically, simulating the movements of copulation, and the male stimulates the female genitals, especially the clitoris, in a similar way, again frequently with rhythmic movements.
The Naked Ape Page 5
